1. Field of the Invention
The present invention generally relates to R-C time constant circuits and, in particular, to such circuits as used to control the duty cycle of a microwave oven power source.
2. Statement of the Prior Art
Resistance-capacitance time constant circuits are well known and have been widely used in various electrical and electronic applications. One particular application in which they have proven to be useful is that of controlling the duty cycle of a microwave oven power source. One reason for this usefulness is that R-C time constant circuits provide more precise timing than the mechanical timers used for a wide variety of appliances and other applications. In addition to the need for accurate control, it is often desirable that the duty cycle be controlably variable.